Fluid couplings consist of two parts which interconnect in a sealed relationship to permit the transfer of fluid therethrough. Such couplings are normally employed to interconnect conduit systems, hoses, and the like, and releasable couplings employ manually operated mechanisms for permitting the coupling halves to be selectively engaged and disengaged.
A common fluid coupling arrangement consists of male and female members wherein the female member includes an axially displaceable locking sleeve having cam surfaces defined thereon for radially displacing detents within the female fitting half. When radially displaced inwardly the detents engage with an interconnected male fitting half to achieve the coupling assembly. Usually, the coupling sleeve is spring biased in the direction displacing the detents, which are often cylindrical balls. However, under shock and vibration forces it is possible for the locking sleeve to be inadvertently displaced sufficiently to permit the detents to be released and permitting the parts to separate.
Also, if the male half is not properly oriented within the female half the detents will not fully engage the male half and only a partial or incomplete coupling may be achieved, and the operator may not sense that the locking sleeve has not been displaced to the full locking position. Upon pressurization of a fluid system having a partially interconnected coupling it is possible for the coupling parts to be separated upon the system being pressurized with disastrous results.
It is an object of the invention to provide a positive union sleeve lock for use with couplings having an axially displaceable locking sleeve wherein use of the lock prevents inadvertent locking sleeve displacement under shock, impact or vibration forces.
Another object of the invention is to provide a positive lock for fittings having axially displacement lock sleeves wherein the lock may be readily manually operated during the gripping of the lock sleeve for manual actuation thereof.
Yet an additional object of the invention is to provide a positive locking feature for fittings having axially displaceable locking sleeves wherein the lock and release conditions of the locking sleeve are readily indicated and discernible by the operator by both observation and touch.
A further object of the invention is to provide a positive lock for a coupling having an axially displaceable locking sleeve wherein safety locking levers mounted upon the locking sleeve automatically pivot to a locking position upon the locking sleeve being displaced to the full lock condition, and manual actuation of the locking levers is only required for release.
In the practice of the invention an annular locking sleeve is mounted upon a coupling half having cam surfaces defined thereon for actuating detents mounted in the associated coupling half. Usually, the locking sleeve is biased by a compression spring toward the locking direction.
At least one safety locking lever is mounted upon the locking sleeve, and preferably, two safety levers are mounted upon the locking sleeve at diametrically related positions. The safety levers pivot about axes or pivot pins substantially parallel to the length of the associated fitting, and the safety levers include an inner portion engaging a reference surface defined upon the fitting while the outer portion of the levers comprise handles capable of projecting radially from the configuration of the locking sleeve when the locking sleeve is in the fully locked condition.
The safety levers are mounted adjacent the open outer end of the locking sleeve, and the associated coupling fitting includes an annular groove or recess having a radial shoulder located adjacent the fitting open end. Once the locking sleeve has been axially displaced by its compression spring to the fully locked condition the innermost portion of the safety levers will be received within the groove and engage the groove and its radial shoulder. This engagement between the locking levers and the groove and shoulder prevents the locking sleeve from being retracted toward the released condition. Torsion springs bias the safety levers in a pivotal direction engaging the safety levers with the fitting groove and shoulder, and the safety levers will automatically be received within the fitting groove only upon alignment therewith when the locking sleeve is displaced to the fully locked condition.
The safety levers are mounted within openings or recesses defined in the locking sleeve, and the levers are of such a configuration as to conform to the normal outer shape of the locking sleeve when the locking sleeve is in the release condition, and a surface defined upon the safety levers engages with a cylindrical surface formed on the associated fitting to maintain the safety levers within their associated opening as not to project therefrom when the locking sleeve is in any axial location except when in the fully locked condition. Upon the safety levers being aligned with the fitting groove and shoulder the inner end of the safety levers is received therein causing the outer handle portion of the safety levers to radially project outwardly from their opening and from the configuration of the locking sleeve. This extending of the handle portions of the safety levers from the configuration of the locking sleeve renders the condition of the locking levers easily observable by the operator, and the safety lever positions may also be physically discerned by touch due to their projection from the locking sleeve configuration.
When it is desired to disconnect the coupling halves, the operator grasps the locking sleeve and simultaneously depresses the handle portions of the locking levers disengaging the levers from the fitting groove and shoulder. Such releasing of the safety levers permits the locking sleeve to be displaced against the biasing action of its compression spring and permits the locking sleeve to be axially displaced to the condition which releases the detents permitting separation of the coupling halves.
The use of the safety locking levers in accord with the invention provides positive restrain against inadvertent displacement of the locking sleeve toward a release condition, and yet, manual release of the locking levers is readily accomplished without necessitating troublesome or complex manipulation. The manufacturing and assembly costs of utilizing a safety locking lever in accord with the invention is relatively small, and the operation of the locking levers requires no special skills.